A lone singer stands atop a barrel of nuclear waste and presents us with his groin as he belts the opening bars of "The Toxic Avenger." Where else could we be but New Jersey?

A lone singer stands atop a barrel of nuclear waste and presents us with his groin as he belts the opening bars of “The Toxic Avenger.” Where else could we be but New Jersey? David Bryan and Joe DiPietro’s adaptation of “a movie most people watched when they were stoned,” as the script confesses, has a fine sense of place, several very funny setpieces and thesps like Sara Chase, Demond Green and Nancy Opel to recommend it. It also has pacing problems and a few gags that run too long, but it manages to thoroughly entertain even when it slacks off.

If you’re some sort of prude who doesn’t find brutal dismemberment funny, you may have a harder time at this show than most. A la “Evil Dead: The Musical,” which occupied the same theater not long back, the offbeat tuner has reserved most of its budgetary resources for splatter effects and bloody prostheses. And, like “Evil Dead,” the “Avenger” team knows you can’t take a man holding a plastic model of a severed leg entirely seriously, so the violence is successfully played for giggles.

Granted, things start out calmly enough. Melvin Ferd the Third (an appropriately earnest Nick Cordero) has decided to clean up the town of Tromaville, N.J., a place even the local nun (Nancy Opel) has trouble singing nice things about (“Who Will Save New Jersey?”). Everyone from the town bullies to Melvin’s mom (Opel again) knows he’s a loser, but the bookwormy teen decides he’s going to take on the Good Earth Corp., which has been dumping glowing green barrels all over town. Shockingly, Mayor Belgoody (also Opel) appears to be behind it all.

Melvin’s budding romance with blind town librarian Sarah (Sara Chase, ever the trooper), and his life as a relatively normal guy are cut short by those bullies (Matthew Salvidar and Green), who dunk him into a vat of toxic goo. Lucky for them, they flee in horror before he’s reborn, Marvel Comics-style, as a huge, molting green dude whose brains appear to be boiling out of his head.

One of the show’s greatest assets is bit player Green, whose antics are exactly audience-friendly enough without seeming hammy. When he plays an evil bully at the town library, he reveals that he’s illiterate by confiding it to Sarah, then turning out and announcing it to the audience with a look of such self-consciousness you can’t help but snicker.

Toxie (to his friends) yanks free an arm from one of the goons and beats him with it (he’s bothering Sarah), and that’s just the beginning. No longer a dweeb, Melvin begins courting Sarah anew and decides to become an environmental hero. Now that he’s not nerdily hunched anymore, Cordero stands 6-foot-several and towers over everyone, including his delighted girlfriend, who makes her peace with the odd smell around her beau.

Helmer John Rando (“Urinetown”) deserves a lot of credit for the gags that go right. So much of “The Toxic Avenger” is in such bad taste that dozens of jokes, especially those about Sarah being blind, threaten to fall flat. They don’t, and Rando frequently employs the script’s running gags to salvage a weak moment in the text.

When, for example, Toxie and Sarah sing a duet (“Hot Toxic Love”), Rando solves the problem of the song’s overlength by simply having Sarah wander offstage, to the consternation of everyone from Toxie to the spot operator. The longer she’s off, the more embarrassed Toxie looks and the funnier the gag is; we forget to be bored by the song.

Then there are the songs themselves — it’s a little hard to believe it took two people to write some of these lyrics. A couple of the rhymes are reasonably clever, but by and large the production props up the material, rather than using it as a springboard. That’s not a judgment on the source — schlock musicals can be fun, as we know from their godfather, “Little Shop of Horrors.” But they still need to be clever and structurally sound.

There are moments that still don’t work, though they’re not fatal. A lengthy, over-theatrical chase sequence is only mildly amusing, and a final battle between two of Opel’s characters (performed in a half-Ma/half-Mayor costume) isn’t terribly funny unless you’re familiar with the embarrassing climax of “Jekyll and Hyde.” To his credit, someone — either Rando or Boritt — has decorated several of the sets with demure photos of “Jekyll” musical star David Hasselhoff as a clue.

And that’s the spirit of the whole thing, really: Fun, worth watching carefully and rewarding mostly to people in the know and in the mood.

The Toxic Avenger

Production

A Jean Cheever and Tom Polum presentation of a musical in one act with music by David Bryan, lyrics by Bryan and Joe DiPietro, book by DiPietro, based on the film "The Toxic Avenger." Directed by John Rando. Music direction, Doug Katsaros. Choreography, Wendy Seyb.